Ron Johnson, Apple’s Senior Vice President of Retail, is set to leave the company in order to take a position as the president, and eventually CEO, of J. C. Penney. The Wall Street Journal reports that Apple is expected to announce Johnson’s departure later today; Johnson will succeed long-time Penney leader Myron Ullman in the CEO position. Apple hired Johnson away from Target in 2000 in order to build out its retail stores, which have…